Time-resolved x-ray diffraction study of solid combustion reactions

Journal Article · Fri Sep 21 00:00:00 EDT 1990 · Science (Washington, D.C.); (USA)

DOI:https://doi.org/10.1126/science.249.4975.1406· OSTI ID:6170409

Wong, J; Larson, E M; Holt, J B; Waide, P A; Rupp, B; Frahm, R ^[1]

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1. Lawrence Livermore National Lab., CA (USA)

Real-time synchrotron diffraction has been used to monitor the phase transformations of highly exothermic, fast self-propagating solid combustion reactions on a subsecond time scale down to 100 milliseconds and in some instances to 10 milliseconds. Three systems were investigated: Ti + C {yields} TiC; Ti + C + xNi {yields} TiC + Ni-Ti alloy; and Al + Ni {yields} AlNi. In all three reactions, the first step was the melting of the metal reactants. Formation of TiC in the first two reactions was completed within 400 milliseconds of the melting of the Ti metal, indicating that the formation of TiC took place during the passage of the combustion wave front. In the Al + Ni reaction, however, passage of the wave front was followed by the appearance and disappearance of at least one intermediate in the afterburn region. The final AlNi was formed some 5 seconds later and exhibited a delayed appearance of the (210) reflection, which tends to support a phase transformation from a disordered AlNi phase at high temperature to an ordered CsCl structure some 20 seconds later. This new experimental approach can be used to study the chemical dynamics of high-temperature solid-state phenomena and to provide the needed database to test various models for solid combustion. 28 refs., 4 figs.

• DOE Contract Number: W-7405-ENG-48; AS05-80ER10742; AC02-76CH00016
• OSTI ID: 6170409
• Journal Information: Science (Washington, D.C.); (USA), Journal Name: Science (Washington, D.C.); (USA) Vol. 249:4975; ISSN SCIEA; ISSN 0036-8075
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360100 -- Metals & Alloys
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400800 -- Combustion
Pyrolysis
& High-Temperature Chemistry
CHEMICAL REACTIONS
COBALT
COHERENT SCATTERING
COMBUSTION
DATA
DIFFRACTION
ELEMENTS
EXPERIMENTAL DATA
INFORMATION
METALS
NICKEL
NUMERICAL DATA
OXIDATION
PHASE TRANSFORMATIONS
SCATTERING
THERMOCHEMICAL PROCESSES
TITANIUM
TRANSITION ELEMENTS
X-RAY DIFFRACTION